Pump



March 20, 1951 F. c. BYRAM PUMP 2 sheets-sheet 1 Filed Feb. 1, 194e ATTORNEYS.

March 20, 1951 F` c. BYRAM 2,545,604

MMMllylg/ www ATTORNEYS.

Patented Mar. 20, 1951 UNITED sTATEs PATENT OFFICE PUMP FrederickCameron Byrain, Springfield, Ohio, as-

signor to Robbins & Myers, Inc., Springfield, Ohio, a corporation ofOhio Application February 1, 1946, Serial No. 644,812

13 Claims. 1

My invention relates to pumps operating on the principle of the U. S.Patent to R. Moineau No. 1,892,217. In pumps of this character in theirsimplest form there is an hollow external element and within it aninternal element, both of them having developed thereon helicalcontours. The helical contour within the outer member (hereinaftercalled a stator), in the simplest form is inthe formof two threads, andon the inner member or rotor there is ya, single thread. In thecommonest form a cross section of the stator presents a straightsided'oval hole at any point. A cross section of the lrotor at any pointpresents a circular outlinewhichcorresponds to the ends of the oval. Thepitch of the thread in the rotor is half that of the pitch of thethreads in the stator. u

In a pump of this character where the stator is held against movement,and the rotor caused to revolve, it is to be noted that the center axisof the rotor must move in an orbital path. The type of pump according toMoineau, which has been used commerci-ally in this country has beendriven by means of a universally connected rigid link. Thus, the drivingshaft is connected by a universal joint to this link and the link isconnected by another universal joint to the end of the rotor. Thisconstruction does not have the compactness and mechanical eiiiciencythat is most desirable and the object of my invention, among otherthings, is to provide an improved driving arrangement for the rotor ofsuch a e pump.

bearing surfaces for the rotor construction. In

such a case, the stator itself may be cut with orifices for exit andentrance into the space between the rotor and stator.

I' have illustrated vin the appended drawings, a preferred but exemplaryform of my invention, and will describe this in det-ail in order toexplain the nature of my invention. In the claims appended to thespecication, to which reference is hereby made, will be found astatement of the novel features which are considered to be my inventionof which the said disclosure is but an example.

In the drawings: v

.Figure 1 is a perspective view of a complete pump according to myinvention.

Figure 2 is a central longitudinal section thereof.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4 is a longitudinal section showing a modification in thestructure of my pump.

Figure 5 is a like section showing a second modification.

The stator structure of the pump in the preferred form is made fromlaminated phenolformaldehyde resin. It has a median circumferentialflange I, and an, elongated hollow cylindrical body 2'. 7 The ends 'ofthis cylindrical body have a serie's'of holes 3v therein for exit offluid and entrance of fluid with reference to the interior of the hollowbody. The interior of the body is formed with a pair of helical threads4,4 extending throughout. If the holes 3 are omitted, then the thrustplates forthe ,rotor tobe described below m'ay be provided with inliuxand efflux orifices. s

I The outercasing of the pump is formed of two heads and 6 which arebolted together through the flange I of the stator. In each head thereis formed a threaded opening I for entrance and exit of fluid to theinterior. Each head has a ange 8 which is seated against the statorflange, the boltsV or screws 9 passing through matching holes serving togrip the stator ange fast between the two headanges.. Y Y

In the form of pump illustrated the head 5 is different from the head 6.This is not necessary as both heads could be the same, but since thedriving shaft must be` provided with a gland of some sort to seal itsentrance and it is only necessary to reverse the direction of drive forthe rotor, to reverse the direction of operation of the pump, it isconsidered simpler to have butA one entrance head 5. This head hasdeveloped thereon a cylindrical body I0, with a journal for the driveshaft I I therein. I have shown a Vbushing I2 serving as a bearing forthe drive shaft at this point. An oil hole and cap I3 provides forlubrication of this bushing. A Sylphon bellow seal I4 is mounted on theshaft and the end of the shaft has a head I5 which is slotted for thereception of a sliding block I6 which may be of laminated phenoliccondensation product material, if desired. e

Where the stator has -a double thread, as by developing an oval shapedhole in a helical curve lengthwise thereof, the rotor I'I will have asingle thread of one half the pitch length of either stator thread. Asalready noted, where variations from this standard are followed, theeiiiciency of the device is sacrificed.

As a convenient way of mounting the rotor, it

is cored out and supported by a spindle I 1a. A thimble i8 is threadedon one end of this spindle, said thimble tting the core of the rotor. Aflange on this thimble at I9 engages the end of the stator. This ange,which is in eifect a thrust plate on the end of the rotor must moveorbitally as well as revolve. By preference the thimble is formed of ahardened metal and is held in place by a nut 18a on the end of thespindle. The drive end of the rotor is equipped in like manner with ahead 2li, which has a transverse slot therein as at 2|. The head has aflange 22, also, which bears against the end of the stator. The flange l9 and the flange 22 constitute thrust bearings for the rotor.

Instead of making the stator of one kind of material as a unit asindicated, it can be built up of different materials secured together.For example, the stator shown could have a bonded rubber core, and ametallic exterior and end pieces for the thrust surfaces.

The sliding block I6 held loosely in the slot of the driving shaft head,also engages loosely in the slot 2| of the rotor head, when the slot inthe rotor head is at right angles to the slot in the driving shaft head.As so arranged a universal but purely torsional drive is supplied, andthere being no requirement on the driving shaft for carrying thelengthwise thrust on the rotor, this .drive is all that is needed topermit the rotor while it revolves at the same time, to rotate about onits axis, .on an orbit, the clearance of the block .from the slots inwhich it is placed aiding in permitting this full movement.

There are various possible modications of the particular structuredescribed.

Instead of using the stator flange as part of the casing of the pump itcan be employed to secure the stator in other ways. Thus in Figure 4there is shown a pump .having a casing 3l) with an outlet orifice 3|,which casing is flanged as at 32 and secured thereby to the head 33,which has the entrance orice 34 therein. The flange 35 at one end of thestator 35 is engaged between the casing 3U and a shoulder 37 on the head33. Also the stator engages a shoulder at 31a on the main casing.

In this instance I have shown a different mode of supplying a puretorque drive to and taking up the thrust of the rotor. Thus the rotor 33has one end bearing slidably on the adjustable abutment post 39. Therotor has `a flange 4B which engages as a bearing on the margin of anannulus 4l developed in the head 33. The thrust on the rotor is thustaken up in the casing but not by means of bearing on the ends of thestator. This leaves the stator open at both ends for influx and efliuxof iiuid during operation of the pump.

In this case I have shown a ball bearing 42 instead of a sleeve orbushing type of bearing for the rotor shaft at one end. As a drive theinner end 43 of the drive shaft, and the flanged end of the rotor areprovided with elliptical recesses 44 and 45 respectively. The margin ofthe annulus di slidably engages the flanged end of the rotor. A drivelink `i8 is provided which is ribbed intermediate its ends and has itsends narrowed to rounded edge blades 49, the ends of which are curvedlongitudinally thereof. The inner ends of the two recesses are alsobrought to a fiat sided conformation so as to take a torque engagementon the narrowed `ends or blades of the link. This drive will be asubstitute for the type of drive illustrated in the other figures of thedrawings, which is known as an Oldham drive. It is immaterial what kindof a single plane torque drive is substituted for the ones shown, and,of course, certain features of my invention are Well adapted for use inpumps which have the normal universal joint connected drive link for therotor.

In Figure 5 is shown a pump for direct attachment to a drive motorcasing. In this instance the drive motor is indicated at 60, and itsflanged housing portion at 5I. The motor drive shaft 62 (suitablysealed) projects into a space surrounded by a flanged ring 63 thatscrews onto the motor housing. The pump rotor Sil, in this `instancetakes its thrust in one direction on the motor shaft. The single planeuniversal drive element G5, which is of the same general construction asthat shown in Figure 2, couples the end of the rotor to the drive shaft.4In this instance the block lEa, corresponding to the block IB of Figure2-, is apertured as at |619, for the passage of the dumb bell shapedpiece 5S, which transmits axial thrust between the drive shaft 62 andthe roto-r 64. The other i end of the rotor bears against a round endedplug 6G in the casing. Instead of this rounded plug a thrust structuresuch as is :shown in the universal drive element B5 may be used. Thusthe rotor shaft may be hollowed out as indicated at 51, at both ends,and the drive .shaft coupling and the plug be hollowed lout as at 68 anda dumb bell shaped piece 69 be used as a thrust member at each end ofthe rotor.

In this instance the stator ila-nge is used in a different way toprovide an immovable mounting for the stator. The stator 1i! has a ange'H which seats on a shoulder 12 in the cylindrical portion .'13 of thepump casing. A ring 13a having ears 74 to receive mounting bolts 15 isbolted in place over the end of the stator ange, holding it firmly onthe said seat.

The balance of the pump casing includes a flanged portion 'I6 which isbolted to the ring 63, in which portion is the entrance opening Tl ofthe pump. The exit opening 'I8 of the pump is in the closed end of thecasing. In this case also I have shown a bypass 19 with a springcontrolled ball check 30 to maintain the pressure of the exit `of fluidsat a controlled value.

From these modifications the man skilled in the art will see variousother modes of utilizing the principles of my novel structure, and it isnot intended by the inclusion of the forms shown to exclude others orexclude ycombinations containing some but not all of the structuresdiierently arranged.

It is intended that the claims that follow ex-v press the noveltyinherent in the exemplary structures, together with the equivalentsthereof.

Having thus described my invention, what yli claim as new and desire tosecure by Letters Patent is:

1. In a pump having a hollow cylindrical stator and a rotor therein, therespective parts having cooperating helical threads and so related thatto revolve the rotor within the stator enforces an orbital path upon therotor, a drive for the rotor including a torsion producing elementarranged to permit orbital movement of said rotor, means for holding thestator against movement, and an independent thrust member associatedwith said torsion producing element for absorbing the axial thrust ofsaid rotor, whereby said torsion producing element is freed of axialthrust.

2. The combination of claim 1 in which means is provided for sealing oneend of the stator from the other.

3. The combination of claim 1 in which the means for holding the statorcomprises a flange on the stator which acts as a barrier between theends of the stator.

4. In a pump having a hollow cylindrical stator and a rotor therein, therespective parts having cooperating helical threads, the stator havingone more thread than the rotor, so that to revolve the rotor within thestator enforces an orbital path upon the roto-r, bearing plates on bothends of the rotor slidably engaging the ends of the stator, and meansfor holding the stator against movement.

5. In a pump having a hollow cylindrical stator and a rotor therein, therespective parts having cooperating helical threads, the stator havingone more thread than the rotor, so that to revolve the rotor within thestator enforces an orbital path upon the rotor, thrust means on therotor arranged to apply thrust in both directions to the ends of thestator, and means for holding the stator against movement.

6. The combination of claim 5 in which the stator has orifices in itssides adjacent its ends for influx and efflux of fluid to be pumped.

7. In a pump having a hollow cylindrical stator and a rotor therein, therespective parts having cooperating helical threads and so related thatto revolve the rotor within the stator enforces an orbital path upon therotor, bearing plates on both ends of the rotor slidably engaging theends of the stator; and means for holding the stator against movement,said pump having casing means embracing the stator, said casing meanshaving parts for each end of the stator, a drive shaft journaled in saidcasing, and a connection between the drive shaft and the rotor having asliding key between the two parts, thus permitting orbital movement ofthe rotor while being rotated.

8. In a pump having a hollow cylindrical stator and a rotor therein, therespective parts havinginterengaging helical threads enforcing anorbital path upon the rotor when revolved within the stator, acircumferential flange on the stator intermediate the ends thereof and acasing for the pump comprising two hollow heads embracing the stator,said heads engaging the said stator flange n and xedly held in suchengagement, whereby the stator is held against endwise and rotarymovement, a rotor spindle and means on the rotor spindle to slidablyengage each end of the stator.

9. The combination of claim 1 in which the pump is provided with acasing and the independent thrust member for the rotor is applied to thecasing.

10. The combination of claim 1 in which said drive includes a driveshaft, and in which the independent thrust member for the rotor isapplied for thrust in one direction at least to the drive shaft for saidrotor but independent of the torsion producing element thereof.

11. In a pump having a hollow cylindrical stator and a rotor therein,the respective parts having cooperating helical threads .and so re latedthat to revolve the rotor within the stator enforces an orbital pathupon the rotor, a drive for the rotor including a torsion producingelement arranged to permit orbital movement of said rotor, acircumferential flange on the stator and a casing for the pumpcomprising two hollow members one of which at least embraces the stator,said members engaging the said flange and xedly held in such engagementfor holding the stator against movement, and an independent thrustmember associated with said torsion producing element for absorbing theaxial thrust of said rotor, whereby said torsion producing element isfreed of axial thrust.

l2. In a pump having a hollow cylindrical stator and a rotor therein,the respective parts having cooperating helical threads and so relatedthat to revolve the rotor within the stator enforces an orbital pathupon the rotor, a drive for the rotor including a torsion producingelement arranged to .permit orbital movement of said rotor, acircumferential flange on the stator intermediate the ends thereof and acasing for the pump comprising two hollow members embracing the stator,said members engaging the said flange and xedly held in such engagementfor holding the stator against movement, and an independent thrustmember associated with said torsion producing element for absorbing theaxial thrust of said rotor, whereby said torsion producing element isfreed of axial thrust.

13. In a pump having a hollow cylindrical stator and a rotor therein,the respective parts having cooperating helical threads and so reu latedthat to revolve the rotor within the stator enforces an orbital pathupon the rotor, a drive for the rotor including a torsion producingelcment arranged to permit orbital movement of said rotor, acircumferential flange on the stator and a casing for the pump, saidcasing having means for engaging said flange and enclosing said flangeat both sides so as to form a barrier between the two ends of the statoron the outside thereof and serving to hold the stator against endwiseand rotary movement, and an independent thrust member associated withsaid torsion producing element for absorbing the axial thrust of saidrotor, whereby said torsion producing element is free of axial thrust.

FREDERICK CAMERON BYRAM.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number Name Date 1,892,217 Moineau Dec. 27, 19322,290,137 Aldridge July 14, 1942 FOREIGN PATENTS Number Country Date113,009 Australia Apr. 28, 1941 360,335 Great Britain Nov. 5, 1931446,291 Great Britain Apr. 27, 1936 534,682 Germany Sept. 10, 1931780,791 France Feb. 11. 1935

